Several neuropsychiatric syndromes including Huntington's disease, Korsakoff's psychosis, Altzheimer's disease, tardive dyskinesia are being studied from the point of view of memory and intellectual function, neuroendocrine function, and possible pharmacological treatment. Procedures used to assess memory function are designed to test (1) short term memory, (2) long term memory, (3) retrieval processing, (4) encoding, (5) factors that influence decay of and interference with memory. Patients with Huntington's disease appear to have a specific deficit in the ability to retrieve information from long term storage. By failing to utilize cues to access memory, Huntington's patients lose the ability to assimilate new information and link this to previous information by sequence or by concept.